Driving belt and pulley.



No. $67,830. Patented Fab. I2, 190|.v A. STEWARD.

DRIVING BELT AND PULL-EY.

(Applicston led June 20, 1900.)

2 Sheets-Sheet l.

(Ho Modal.)

l/A/ VEA/Tof? W/ 7'NESSES No. $67,830. Patented Feb. I2, I90I.

A..sTEwAnn.

DRIVING BELT AND PULLEY.

:Application led June 20, 1900.)

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AUREIJIUS STEWARD, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE VHEELER d: WILSON MANUFACTURING COMPANY, ORSAME PLACE.

DRIVING BELT AND PULLEY.

SPECIFICATION forming` part of Letters Patent No. 667,830, dated February 12, 1901. Application filed June 20, 1900. serial No. 21,008. (No model.)

To cz/Z/ whom, it 7mo/y concern:

Be it known that I, AURELIUS STEWARD, a citizen ot' the United States, and a resident of Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Driving Belts and Pulleys, of which the following is `a speciication.

My invention relates to driving mechanism io for use with shafting where constant and uniform regularity ot motion is required, as in sewing-machines and the like, Where mechanism driven by one shaft must work in eX- act time and unison with mechanism driven by one or more cooperating shafts, and hence where no slipping, as of an ordinary belt, can be allowed.

I am aware that non-slipping belts have been employed which were provided with 2o holes to engage corresponding spurs set in pulleys; but these are found objectionable both on account of the tendency of the holes to be drawn farther apart and also to be stretched and worn oblong to so great a degree as to destroy the necessary accuracy in the movements of the cooperating parts, which objection is overcome by a belt constructed as herein described. In the construction of a belt for such purposes I use a cord which 3o forbestresults is composed of the iinest,long est, and most inelastic iberand of a size and strength commensurate with the power which the belt is intended to convey or the labor it is intended to perform.

In the accompanying drawings,which form a part of this specification, Figure 1 represents a pair of shafts with their applied pnl leys and equipped with my improved belt. Fig. 2 is one of the pulleys enlarged to bet- .4o ter show its formation. Fig. 3 is a Vertical sectional view of the same and a portion of the belt as applied. Fig. 4 is a perspective view of the belt as completed. Fig. is an enlarged perspective view of one of the clamps as formed preparatory to placing' upon the belt; and Fig. 6 is a clamp, also in perspective and enlarged, as shaped when clasped upon the belt.

Like letters designate like parts through- 5o out the several drawings.

As seen in Fig. l, A A represent a pair of shafts, which may be of ordinary construction. B B are pulleys, and C a belt, each of my special construction. b b are flanges on each side of said pulleys, and ZJ represents grooves made longitudinally with the shafts in the belt contact-surface of the pulleys. c represents the parallel-lying layers of cord which constitute the belt, and cl metal clamps which embrace said layers of cord and hold 6o them permanently together.

The flanges ZJ upon the pulleys, though sometimes desirable, are not especially an essential element ot their construction.

The grooves b in the pulleys are of suliicient depth that the clamps will have no contact with the bottom of the same and of snfiicient width that the clamps may enter freely and without contact, except upon that side of the groove toward which the strain ot' the 7o belt would tend to incline them, as shown in Fig. 3.

The grooves in all pulleys driving or being driven by the same belt are exactly equidistant in order that all of said grooves may coincide with the clamps upon the belts.

The belt C is preferably formed of one contin nous cord, whose successive layers or coils are laid closely together side by side in sufiicient numbers to constitute collectively the 8o Width of the belt desired and the ends of the cords so overlapped that both may be embraced by atleast one of the clamps, as shown at CZ', Fig. 4. The clamps d, having been bent into form, (shown in Fig. 5,) are placed around the several coils of the cord and then so compressed that the ends may meet, as shown in Fig. 6, and the parallel inner sides of the clamps embedded into the yielding surface of the cordssuiticiently to hold them against dis- 9o placement by any usage to which the belt is liable to be subjected.

To produce a belt which is practically inelastic and which will retain the same length through all conditions, I have found fibers possessing the qualities of length and inelasticity to the greatest degree, such as ne linen fiber, to be preferable in order that but a small amount of twist may be required to hold the ber in place, and by the use ot' such fibers roo and the application oll the clamps at short intervals, which confine and prevent the fraying of the fibers, the amount of twist required in the manufacture of the belt is reduced to a minimum.

It is found that fibers of the class above mentioned partake of the character of wood and are not expansive longitudinally to any appreciable extent, and cords composed of such fiber, if but slightly twisted, partake of the same character. In such slack-twisted condition the fibers all lie practically parallel with the cord, and their expansion laterally by dampness, to which they are very susceptible, does not affect the belt longitudinally to any appreciable extent. Vhen the strands composing` a cord are much twisted, however, the individual iibers become coiled, and consequently exceedingly elastic, and the elasticity of the finished cord is thereby greatly increased, and the individual strands which compose the completed cord are made to lie so much transverse to the line of the cord that the expansion and cont-raction of the fibers transversely by climatic changes to which a belt may be subjected so aifects the length of the belt as to destroy its practical utility.

As a means of forming the belt to an exact and predetermined length I have found it most convenient to form it upon a cylinder whose circumference equals the lengthof belt required and after inserting the clamps into equidistant and closely-fitting grooves in said cylinder to compress said clamps upon the belt while the latter remains in that condition. As an exact length is a necessary requisite in such a belt, the inner surfaces of the clamps are made plain that they may compress the cord without corrugating it, and hence the belt is not shortened by their application. As

they are compressed upon the belt to secure them against displacement, the fibers, while compressible transversely, are not affected longitudinally, and the compression has lno perceptible effect upon vthe length of the belt, the accuracy of which is one of its most essential requisites.

It Will be seen from the foregoing description that the clamps upon the belt serve a double purpose, first, to engage the pulleys with practically the same certainty as geared wheels, and thereby insure the working of the shafts in exact unison, and, second, to so secure the fibers in the cords as to render unnecessary a degree of twist sufficient to destroy the inelasticity and stability, which are indispensable in belting when employed for the purposes described.

The metal of Which the clamps are composed is of such density or consistency and temper that when compressed there will exist no perceptible tendency to spring apart or open andrelease the cords inclosed in their embrace.

The clamps are placed equidistant upon the belt, the distance being such as to correspond with the grooves in the pulleys, as shown in Fig. 3.

I/Vhile it is preferable to construct each belt with one continuous cord, yet many pieces may be used if ends are properly overlapped and secured beneath the clam ps without serious detriment and without departing from the spirit of my invention.

Vhat I claim as my invention, and desire to secure by Letters Patent, is-

l. In an endless driving-belt, the combination of a substantially inelastic cord wound A in successive coils of predetermined lengths side by side in sufficient numbers to constitute the Width of belt, with a series of clam ps secured thereon and adapted to cooperate with corresponding grooves in pulleys engaged by said belt, each of said clamps being formed of a single piece of metal bent into substantially oblong shape around said cordcoils and pinched or compressed thereon sufficiently to prevent displacement, substantially as and for the purposes described.

2. In a power-transmitting apparatus, a substantially inelastic cord wound in a series of coils side by side and su fficient in number to constitute the width of a belt, and aseries of equidistant clamps embracing said coilsv and compressed thereon sufficiently to prevent displacement, combined with pulleys provided with equidistant grooves to correspond and cooperate with the said clamps, substantially in the manner and for the purposes set forth.

Signed at Bridgeport, in the county of Fairfield and State of Connecticut, this 16th day of June, A. D. 1900.

- AURELIUS STEWARD. Witnesses:

J. S. FINcH,

C. N. WORTHEN.

IOO 

